This invention relates to a method of predicting ink consumption in a gravure printing process. Such a process may use an electro-mechanically engraved gravure printing cylinder; for example, a gravure printing cylinder which has been engraved in accordance with the method disclosed in copending application, Ser. No. 08/022,127, filed Feb. 25, 1993. Such printing cylinders are engraved by an engraving head comprising a diamond stylus carried by a holder mounted on an arm projecting from a torsionally oscillated shaft. A sine wave driving signal is applied to a pair of opposed electromagnets to rotate the shaft through an arc of approximately 0.25.degree. at a frequency in the neighborhood of about 3,000 to 5,000 Hz.
A video signal is added to the sine wave driving signal for urging the oscillating stylus into contact with the printing cylinder thereby engraving a series of controlled depth cells in the surface thereof. The printing cylinder rotates in synchronism with the oscillating movement of the stylus while a lead screw arrangement produces axial movement of the engraving head so that the engraving head comes into engraving contact with the printing surface of the printing cylinder. The system has setup controls for quickly and easily setting up the engraving head to engrave cells of precisely controlled dimensions in the surface of a gravure printing cylinder.
When such a printing cylinder is used in a gravure printing process, ink will be applied in an amount which is related to the total volume of all of the cells which have been so engraved. This is likewise true for gravure printing processes using printing cylinders which have been engraved by other engraving techniques. Regardless of the particular engraving technique which is used, it has been common to engrave connecting channels between cells having a depth which is greater than some predetermined amount. This has complicated the task of predicting the amount of ink which will be required for a particular printing job. Heretofore, ink volume estimation has required a tedious trial and error process and has been subject to error. This has made it necessary to stock excess amounts of ink in order to avoid shortages.